Sunday, July 31, 2011

Atlantic Blobette: July 31, Update A

That blobette I mentioned a few days ago has put on a nicer frock now (maybe in the casual summer dress range, not quite yet an evening gown ;-)).

However it is still somewhat disorganized, and it is spread out over a broad area with some pretty decent circulation in the lower parts of the troposphere, centered around 13-14N, 51-53W, and some circulation in the upper half of the troposphere, centered around 13-14N, 48-49W. The wind shear is also skewed, with more to the north of the system than to the south.

It has been trying to get the convection we need, but that’s still a little scattered as well with more on the western side than the eastern. This is partly because the western is now over ocean waters that are warmer than 26 deg C over the upper 100m of the water column, whereas on the eastern side they are warm only over the upper ~50m. As it moves WNW (at 15mph), it will eventually be over the deeper warmer water region and we should see convection pick up.

They are sending in a plane to investigate this afternoon and they have the ‘chance of it becoming a tropical cyclone’ (note: lower case J) at ‘near 100%’ (not quite sure why they bother with this level!), so I am expecting to have a Tropical Depression or a Tropical Storm by the end of the day.

Given the broad area this is spread over, and more importantly, given that there is circulation in the upper troposphere, *if* this system gets its act together before reaching the Windward Islands, I think there is a good chance this could be our first hurricane of the season.

I’ll pop back with an update once this one puts some make-up on. ;-)
Laters!
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Saturday, July 30, 2011

Tropical Depression Don: July 29, Update B

Tropical Storm Don deteriorated rapidly before officially making landfall, so he was just a Tropical Depression with winds of 35mph (central pressure 1006mb) when he made landfall in Baffin Bay at around 10 pm local time. His convection collapsed within 3 or so hours, and all that is left of him now are some clouds and small pockets of rain as shown in the IR satellite image taken about 1-1.5 hours after landfall.



Although the NHC say he will dissipate in a day or so, I am writing him off now… it’s a Saturday tomorrow, and I have fun Saturday sorts of things to do instead. Like dishes. And laundry. And vacuuming. And other such exciting things. It’s ok, you can admit it, you are envious aren’t you? ;-)

This is my last entry on this system… I’m done with Don! Hurray!! J   

That’s it until the next system, which once it forms will go by the name ‘Emily’.   

Toodle Pippy!
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Friday, July 29, 2011

TS Don: July 29, Update A

A quick note: TS Don’s outer rainbands have been moving onshore over southern Texas/Mexico during the day today. The center is still offshore at around 26.6M, 96W and is moving WNW at 15mph – a few more hours to go until landfall. Winds have remained at near 50mph (from a plane, and also just under that from satellite information). Central pressure is 1004mb, so fairly high already. This is obviously more of a rain and thunderstorm event than a wind event.

I’ll be back later, once he’s made landfall.
Until then,
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Thursday, July 28, 2011

TS Don & Atlantic Blobette: July 28. Update C

TS Don:
Well I have returned from having a glass of wine and lo-and-behold the NHC and I are, indeed, in better agreement since the earlier entry! The NHC relocated the center southward and it is now at 24.7N, 92.5W, moving WNW at 14mph. It is also quite a bit more towards the west than previously stated (hmm… perhaps where it might have been if it had been moving WNW all along instead of NW). The forecast track has been moved southwards, with the center of the cone of uncertainty now south of Corpus Christi and currently potential landfall may be more likely closer to the Brownsville/Rio Grande region (southern Texas/Mexico area) around midnight tomorrow night. Also, the central pressure has now been decreased to 998mb (based on observations from two aircraft) and sustained winds have increased to 50mph. As you know I’m not very opinionated (ha ha ha), but I do approve. The NHC reason for this change in center and track is that Don jogged ‘temporarily westward’.

Now that’s been sorted out I can think about the intensity. Don has just finished crossing the Loop Current. Although he is still over water with temperatures around 30 deg C, those warm waters are not as deep as in the Loop Current. Combining this with the light wind shear means that I don’t really expect him to get any stronger than he is at the moment (50 mph) and I think there is even a chance that he will weaken before landfall.

Atlantic Blobette:
There is a little blobette waaay out there. It has some decent very low tropospheric circulation, and some convection, however the two are not in the same place and there isn’t any mid-to-upper level circulation yet. I’m not going to mention this one again unless it puts on a nicer frock.

That’s it for today. We’ll see what tomorrow brings.
Toodles!
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Tropical Storm Don: July 28, Update B

Hmm… something funny is going on. Either my crystal ball needs a good scrubbing and the satellite images I’m look at are all wrong, or the NHC isn’t looking at what I’m looking at. I know they have been flying planes through TS Don, but the latest discussion says:
“DATA FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT SHOWED THE CENTRAL PRESSURE RISING TO 1005 MB...WHILE THE AIRCRAFT WINDS SUPPORTED AN INITIAL INTENSITY OF 40 KT.”

A rising central pressure? 40 knots translates to about 46 mph (1 knot = 1.15 mph). Unfortunately there is no direct high-resolution satellite pass of winds in this section of the Gulf available (to me) at the moment, and there are no buoys or other observations (because why would we need those?), so we have to rely on what the data collected by the plane shows and also on the images of this storm from the GOES satellite. The last NHC advisory had the storm center at 24.9N, 91.3W, moving NW at 16mph. The images attached here are the IR and visible satellite images that I grabbed an hour and a half or so after the last advisory.



If someone can see how the center is a little northwest of 24.9N and 91.3W (I marked an approximate location with a red dot on the visible image), then please let me know because to me it looks a little on the edge of the system. Either I need new glasses (quite likely ;-) ), or the plane is going through the wrong part of the storm which is why they are detecting an increase in pressure – but that doesn’t seem likely either, which is why I’m a bit befuddled.

There is a bit of wind shear (5-10 knots) but convection in this storm has progressively got stronger during the day, as you can see from the large red and bit of grey in the IR image. If they are correct, then landfall will be tomorrow night in the Corpus Christi area (as the current forecast center of cone line shows), however the bulk of the bad weather will be south of that.

I’ll stop by later and see if our opinions line up – I’ll have had a glass of wine by then, so I might be able to see things more clearly! ;-)

Ciao,
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Tropical Storm Don: July 28, Update A

Deary me but TS Don is a messy looking storm at the moment!



It is still a bit tricky to see where his center of circulation is because he is still fairly weak. The NHC, based on data from a plane that flew through him this morning, say it’s around 24.6N, 90.7W and he is heading NW at 15mph. I still don’t quite see that center of circulation and think he might be a little south of that location and moving a little more WNW. Regardless, they have shifted the forecast track southwards a bit, so the center of the cone is now in southern Texas. I think that might get revised a little more to the south – but they do have the best data directly from in situ measurements (meaning in position or at the site, in this case via the plane), versus my data which is obviously based on a crystal ball ;-).

It is no surprise that the plane (or rather the instruments and people in the plane) found that he had intensified slightly, and has sustained winds of 45mph (TS range: 39-73mph). He is moving away from the influence of the Yucatan landmass.

It looks like a few of you actually read my earlier notes on tropical storms and Tropical Storms and even made coherent comments! ;-) Clay from Georgia asked a clarifying question on whether storms in the Indian Ocean or Pacific that have wind speeds of less than 73 mph are named or not. Storms in the other ocean basins that reach winds of over 40mph are also named, but they go straight to ‘Cyclone’ or ‘Typhoon’ (basin-dependent), they do not pass ‘Go’ (Monopoly reference ;-)), and don’t have a divide between ‘Tropical Storm’ and ‘Hurricane’ as in the Atlantic/eastern Pacific.  Also, Cyclones and Typhoons are not usually given a category based on wind speeds like we have Hurricane Cat 1-5, so if you hear about one of those storms you need to also know the wind speeds to figure out how strong it is. The exception to this are Super Typhoons, which have wind speeds of 150mph or higher, and are therefore the equivalent of a very strong Category 4 (range: 131 - 155mph) or stronger Hurricane. And Jeff from Florida wins the fellow-geek yellow jersey for today for being the first to correctly identify my slightly geeky reference to Masters of the Universe/He-Man (“the Power of Grayskull”) – to Jeff’s wife: please rest assured your husband is *not* a wealth of useless information. ;-)

I’ll be back later.
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Tropical Storm Don: July 27, Update C

The hurricane hunter plane found that our little Caribbean/GOM blob had a good enough structure to become Tropical Storm Don this afternoon. He is in the Gulf, just north of the Yucatan peninsula, with a center officially around 22.8N, 88.1W. Because he is not very well organized yet, it is difficult for me to see this center and I would hazard a guess that he is actually a little south of this location, which would make him a little closer to the Mexico landmass. Because of this proximity to land his convection has decreased a little this afternoon/evening and he is barely a TS with a wind speed of 40mph (TS range: 39-73mph) and central pressure of 1000mb. As he moves away, he should get a bit stronger.

He is moving WNW at 12mph. The forecast has him making landfall on the central Texas coast on Friday night as a Tropical Storm. I think he’s got a good chance of carrying on in a more westward direction than the forecast currently shows, so this landfall might be a little too far north. It could be a Mexico/south Texas landfall, but I won’t be able to tell until I get more data tomorrow.

Someone (Jack) sent me a question today about why this was being called a tropical cyclone and not a tropical storm. This is an excellent question that I’ve never had to try an explain in writing before, and nope, it’s not to scare people ;-) … it’s just meteorological jargon to keep us on our toes. Hopefully this is where I’ll only lose about 99% of you… here goes…

1. All low pressure systems have what is called <jargon alert> cyclonic motion <end jargon alert>, regardless of which hemisphere they are in (I’ll go into hemisphere and direction of movement some other time).

2. So tropical cyclones (lower case), which are low pressure systems, are the generic name for all tropical storms (also lower case) regardless of which ocean basin they develop in. The terms ‘tropical cyclone’, ‘tropical storm’, and sometimes ‘tropical system’ are interchangeable (so long as they are all pronounced with a lower case of course) and do not have names.

3. However, (and here’s a magic trick so pay attention otherwise you’ll miss it), if these tropical cyclones (lower case) develop in the Indian Ocean, they are called Tropical Cyclones (upper case) and have a name. (Did you like that very subtle lower case/upper case trick, huh? ;-) ). In the Atlantic and eastern Pacific, named tropical cyclones (lower case) are called Hurricanes (upper case), and in the western Pacific, named tropical cyclones (lower case) are called Typhoons (upper case). And of course, just to make things absolutely crystal clear for you, if a tropical storm/cyclone (lower case) has winds of 39-73mph and develops in the Atlantic or eastern Pacific, it is called a Tropical Storm (upper case) and given a name. So if you catch someone pronouncing a lower case tropical cyclone/storm in an upper case, or vice versa, then you should report them to the Ministry of Incorrect Case Usage, located next to the Ministry of Silly Walks ;-).

4. This terminology is well established and came about historically. It is beyond even the Power of Grayskull to change this now so we just have to live with it.

Well that was fun. Are you still with me? Hello? <chirp chirp> Er… hello…? <tumbleweeds> Hmm… I think I’ve lost you all. It must be time to go. I’ll give you time to read that again and I’ll be back tomorrow (did I mention the test at the end of this season? ;-)).

Night!
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Wednesday, July 27, 2011

Caribbean/Gulf of Mexico Blob: July 27, Update B

Quick update: The wind shear has diminished and circulation in the lower half of the troposphere is good now, so we have the structure of a tropical storm and I would upgrade this if I had my druthers. Convection continues to look strong too. The NHC have sent a plane in to check it out before they upgrade it, but they say ‘near 100% chance’ of this being a TS. I expect you will see TS Don in the next hour or two and I’m estimating the winds (from satellite wind data) to be in the 40-50mph range, with gusts in the 50-60mph, but the plane will return more accurate information. It is partly in the Caribbean and partly in the Gulf now, moving WNW at about 15mph. Once this clears the Mexico/Cuba landmasses it should be a “fun” system I think.

I find it interesting that they are so cautious about storms that clearly look like tropical systems, but will classify/name storms that are outside of flying range and don’t have the same features.

Ciao for now,
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Caribbean Blob: July 27, Update A

The Caribbean blob and our potential next Tropical Storm, Don, is improving in looks (and perhaps also in personality?). It has very good circulation in the lower troposphere over the Yucatan Strait. It also has circulation in the middle levels of the troposphere, but due to wind shear, that is currently sitting over the western tip of Cuba, so the overall vertical structure is not quite cohesive enough to be a Tropical Storm. However, I have noticed once in a while that little things like physics and nature are not allowed to get in the way of a good story, so I suspect that it will become a named Tropical Storm later today. ;-)

Convection is certainly running amok with lots of good thunderstorms in the area. Here’s an infra-red (IR) satellite image of this blob.



I don’t think I have got around to writing my ‘How to interpret an IR satellite image 101’ this year, although I’ve mentioned that red (and dark grey) are strong thunderstorms, possibly tornado generating, orange is thundery with heavy rain, yellow is just rain, blue is just cloudy, no rain, and light grey/white are lovely, whispy or fluffy bunny-rabbit (that’s a technical term for ‘cumulus’ clouds of course ;-)) summer-day sorts of clouds. <Science Alert> The IR satellite image shows the temperature of the tops of the clouds. In the troposphere, the higher up you go in altitude, the warmer the temperature becomes (this trend changes direction for the next layer in the atmosphere which warms with height. This next layer up is called the stratosphere and is where the ozone layer/hole likes to hang out). The stronger the convective activity, the taller the clouds are, and the warmer the cloud tops will be. So red areas on this IR image is where the cloud top temperatures are warmest, orange are not so high up and so on. <End of Science Alert>

Looking at the larger scale pressure fields, it looks like this blob will continue to move in a general WNW direction for now, and therefore into the Gulf. I’ll report back later with where it’ll be after that. The models are showing the TX/LA region for landfall, which is indeed a likely scenario.

Don is very international as names go. I mentioned India and Italy(US) yesterday, and here’s an Australian, “Don Bradman = legend” (from Steve B.). Sir Donald George Bradman, called “The Don”, was one of the greatest cricket batsmen of all time, with a Test batting average of 99.94, which is “claimed to be statistically the greatest achievement in any major sport.” If you disagree about the statistics (not about whether cricket is a major sport part because it is!!), please take that up with Wikipedia. ;-)

More later… I’m out for now!
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER: These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Tuesday, July 26, 2011

Caribbean Blob: July 26, Update A

Hmm… I’ve been watching this blob spend the last few days slowly moving westward, dumping rain on the northern islands of the Caribbean, and sampling the rum-based drinks along to be found along its path. Finally, today, it had some Cuban coffee and started sobering up and becoming organized. It has almost cleared Cuba and is in the north-western Caribbean, moving generally west-northwestward. Circulation has improved in the lower levels of the troposphere and convection is strong enough for thunderstorms. It is a bit too soon to tell, but it could go anywhere from westward across the Yucatan peninsula to west-northwestward(ish) through the Yucatan Strait and into the Gulf.

One reason I’m watching this blob carefully is that once it completely clears Cuba it will be over waters where the upper 125m are warmer than 26.5 deg C, which means it will have plenty of warm water even if it churns it up from depth. However, to counter this at the moment the wind shear is a little too strong for this system to cope with, so it may develop slowly. It’s still too early to say if this blob will need another cup of coffee or not.

The next named storm will be called Don. Now there’s a name that conjures up all sorts of associations! A synapse in my brain that hasn’t seen the light of day for a few years is the Indian movie called Don (made 1976), that I watched way back when four wheel cars were new on the market. It starred one of the biggest stars of ‘Bollywood’ at the time - Amitabh Bachchan. I see they re-made it in 2006 (I assume it’s a remake), with one of the most popular movie stars on the planet – Shahrukh Kahn. I might have to see if I can get my paws on that one just for a laugh. And of course, there’s the immortal Don Corleone from The Godfather <insert haunting Godfather music>.

I’ll let you know if this blob makes a move towards being the next Don!

Toodles for now!
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Thursday, July 21, 2011

TS Bret, TS Cindy, and another Atlantic Blob: July 21, Update A

Sorry about the silence yesterday! I’m actually on another planet (that materializes once around this time every year in San Diego) and in my long journey here, I had a few computer glitches. C’est la vie. But I see that all is progressing in the Atlantic according to my plan, so it’s ok. ;-)

TS Bret: Really, I don’t consider him a tropical storm any more, and haven’t done so for a day at least. His convection has been dodgy for the past couple of days, and although he still has some circulation, the official wind speed has been held steady at around 40mph (TS range: 39-73mph) but the pressure has been increasing. Hmm. How did he manage that? Nope, I think he’s just a depression now. Currently central pressure is 1007mb and he is moving ENE at 10mph. I expect him to be downgraded in the next few hours and this is my last entry on Bret.  Bye Bye Bret.

TS Cindy: What a waste of a storm name! Yesterday when she was upgraded, she only had circulation in the very lowest sections of the troposphere – nothing in the mid or upper levels and there wasn’t much convection. Water temperatures were 25-26 deg C (and she’s now over even cooler waters)! This isn’t even enough to sustain a storm, let alone allow one to develop. At the most I’d say she was a subtropical storm, but officially they called her a Tropical Storm. She has estimated winds of 60mph, and an estimated central pressure of 1002mb. She is located at 42.3N, 45W, moving NE at 28mph(!) and circulation has improved in the lower half of the troposphere. But with that forward speed and given her location and the cold sea surface temperatures, I don’t think she’ll remain a Tropical Storm for much longer and they will transition her into an extratropical system any second now.

Atlantic Blob: There’s another blob in the Atlantic that the NHC are watching. I know, this is getting a bit silly isn’t it? ;-) This one is at around 15N, 50W. But there isn’t much convection and only a bit of circulation in the lowest levels of the troposphere. It’s rather disorganized.  I’ll keep an eye on this next Atlantic Blob and send out a short word (by smoke signals if I have to!) if it looks like it’s going to make a move.

Until then, I’m going to hang out with some aliens, eat ice cream and popcorn sandwiches, and drink wine (on this planet no-one has what we on earth consider a healthy diet). ;-)

Live long and prosper,

J.

 

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Wednesday, July 20, 2011

TS Bret and an Atlantic Blobette: July 19, Update A



TS Bret is currently at around 30.8N, 74.8W, and is moving NE at 8mph. Winds are now officially down to 50mph, making him a weak-ish sort of storm (central pressure 999mb). As you can see from the attached satellite image of Bret, there are lovely whispy clouds in the northern and eastern side of the system, with some heavier clouds (no rain) in the southwest quadrant. As I thought yesterday, the wind shear really was not enough to compensate for the other factors that were working to stop him from intensifying further. With such little convection, I don't really consider this a tropical storm anymore, but there is still some decent circulation in the lower half of the troposphere so the NHC will probably keep Bret as a TS for a little while longer.

There's another blobette farther out in the Atlantic. This one also does not have a lot of convection and is not very well formed yet. It is centered somewhere around 33N, 58W so it's east of Bermuda, and it is moving towards the east. Even if it develops it will remain in the Atlantic, well away from land.

It's a bit late in my corner of the world, so time for a nice nap now... more tomorrow.

Toodle pip!
J.

p.s. In case you were wondering about the fate of TS Dora from yesterday's satellite pic, she is now a hurricane in the Pacific and may clip the Mexico/Baja peninsula over the weekend.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Monday, July 18, 2011

Tropical Storm Bret: July 18, Update B

TS Bret is a very well behaved storm, isn’t he? (well… apart from the sneaking up when I’m not around bit ;-)).

He has been steadily intensifying as expected and now has winds of about 65mph (TS range: 39-73mph) which makes him a strong Tropical Storm. Central pressure is 996mb. He made that North-Northeast turn, also as expected, and is now heading NNE at 7mph so he is moving away from the Bahamas and out into the open ocean. He is currently centered at around 28.5N, 76.8W.

I agree with the NHC track that he will begin to move towards the NE soon (actually, it looks like he is already moving in that direction). He may strengthen a little more, but I am not totally convinced of this and at the moment I don’t see any signs that he will make it to hurricane strength. The only reason he might intensify further is because wind shear is low and will remain low for a few more hours, but there are a few factors working against his intensification. For a start, there is no real circulation in the upper troposphere, which is something we always see with hurricanes. Also, the circulation at the lower levels of the troposphere is not a very well defined circular shape – it’s a bit wibbly-wobbly and elongated. Another factor is that although Sea Surface Temperatures (SSTs) are over 29 deg C, and are therefore warm enough to sustain a storm (need SSTs greater than 26.5 deg C to sustain a storm), the warm water is a very shallow layer at the surface of the ocean so as he churns up the waters underneath, he is pulling up cooler water. If it was warmer with depth, then I’d be a bit more concerned. And finally, he is pulling dry air into the storm, so the convective activity is already decreasing. Here is a NOAA satellite image (infra-red) of the convection across the Western Atlantic, Caribbean, Gulf of Mexico, and Eastern Pacific:



Bret is the yellow/blue blob just north of the Bahamas and east of Florida. The other Tropical Storm on this map is in the Pacific – the red/orange/yellow/blue blobette at around 10N, 95W is TS Dora. Red colours indicate strong thundery weather, yellow is rainfall with little-to-no thunder, and blue is just cloudy no rain. You can see the difference in the amount of convection between the two Tropical Storms… Bret looks a bit wimpy in comparison to Dora (she may become a hurricane in the Pacific within a day or so

I’ll continue to keep an eye on him (to make sure he continues to behave!), but I don’t think he’ll be too much of a bother to anyone (unless you are sailing in that part of the Atlantic… in which case it might be a tad bit rocky). I imagine the surf is not bad along the Florida Atlantic coast though. J

Oh look, it’s ice-cream-o-clock!

Ciao for now,
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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Tropical Storm Bret: July 18, Update A (written on 17, posted after midnight)

Oh bother... I forgot to tell Mother Nature I was taking a week off. I *knew* I forgot something! I suppose it's a wee bit too late now, huh? Ah well, so long as you don't mind me writing with an experimental orange martini in one hand... ;-)

I see that little Tropical Storm Bret was named at 5pm EST today, with winds around 40mph (TS range: 39-73mph) and a central pressure of 1009mb. He is currently centered at 27.1N, 78W and since his formation (9 hours ago), winds have increased slightly to 45mph and pressure has decreased to 1002mb. Although he developed near the Bahamas, he was actually part of a larger low pressure trough that extended all the way from the southern half of the Florida peninsula, out into the northeast Atlantic - yesterday he was a just a blob in string of blobs, but in the last few hours his circulation has improved throughout the lower half of the troposphere and so I agree, we have a tropical storm

He hasn't really moved much since he was named - the latest official word from the NHC is that he is 'moving' SSE at 4mph (i.e. he's pretty much stationary). It does look to me that he will begin to move towards the North-Northeast soon, and in that I think I agree with the NHC.

Over the past few hours, in addition to stronger circulation, the convective activity in Bret has improved near the center, which is why he is slowly strengthening. It looks like parts of the Bahamas are getting a bit of a soaking. Lucky I didn't go there for a holiday... I didn't really want "umbrella" drinks ;-).

Hmm… speaking of which, time to get back to my neglected martini. We'll be Back with Bret tomorrow.

Until then, night night!
J.

Blogs archived at http://jyotikastorms.blogspot.com/
Twitter @JyovianStorm

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DISCLAIMER:
These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.
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